398 Forestry Quarterly 



These values set in the fundamental formulae stated above and 

 subtracted, reduce the equation to : 



K\.opr 

 and setting in for K the original form the final formula becomes 



a; = 100 -^^+^~^'- 



That is to say, the net yield increment /r+i— /r appears as rent of 

 the net yield /r that could have been drawn in the year before. 



With this end result the concepts of stand value and soil value 

 become vmnecessary; it is only necessary to know the net yields 

 to develop this index per cent. 



The author adds that rotations figured with this per cent are up 

 to thirty years longer than those calculated with the gross yields 

 of the soil rent theory, the low rotations of which have always 

 been a stimibling block. 



Zur Umlriebsbestimnung der Wdlder. Zeitschrift fur Forst- und Jagd- 

 wesen, September, 1914, pp. 538-549. 



In a discussion at the Austrian Forestry 

 Forest Congress, June, 1914, Dr. Hufnagel pointed 



Valuation out the necessity of formulating procedure 



in valuing both farm and forest property, 

 especially for public purposes. Such valuations are either for 

 purely fiscal purposes, like taxes, or cases in which the interest of 

 third persons is involved, like bankrupt proceedings, executive 

 sales, inheritances, etc. Valuation by sale value presupposes 

 a division of the property into parts ; valuation by yield value pre- 

 supposes management of the whole; valuation by productive 

 value represents the lowest price at which an owner may give up 

 a property without loss. Since forests as a rule are to be con- 

 sidered as a unit [a managed forest is supposedly meant. — Ed.], 

 they should be valued by their yield value with a difference ac- 

 cording to whether taxatory or other considerations are to enter. 

 In the first case only that yield is to be used which under or- 



